<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>贝塞尔曲线</title>

    <style>
        canvas{
            border: dashed 2px #ccc;
        }
    </style>

    <script>
        function draw(){
            let canvas = document.getElementById('canvas');
            if(canvas.getContext){
                var ctx = canvas.getContext('2d');
                for (let i = 0; i < 4; i++) {
                    for (let j = 0; j < 3; j++) {
                        ctx.beginPath();
                    }
                    
                }
            }
        }
    </script>
</head>
<body>
    <div>
        <canvas id="canvas" width="600" height="600"></canvas>
    </div>
</body>
</html>